Malagelada JR, Malagelada C. J Pediatr Pediatr Med. 2018; 2(3): 21-27 Journal of Journal of Pediatrics and Pediatric Medicine Pediatrics and Pediatric Medicine Mini Review Open Access Management of irritable bowel syndrome in children Juan R Malagelada, Carolina Malagelada 1Digestive System Research Unit, University Hospital Vall d’Hebron, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain Article Info Article Notes Overview Received: April 23, 2018 Accepted: June 28, 2018 *Correspondence: IBS is a clinical condition involving frequent (≥4 days per month) Dr. Juan R Malagelada Digestive System Research Unit, University Hospital Vall and chronic (>2 months) abdominal pain and stooling disturbance. d’Hebron; Centro de Investigación Biomédica en Red de Bloating is a common and highly annoying accompanying symptom. Enfermedades Hepáticas y Digestivas (Ciberehd); Diagnosis is established by applying symptom criteria elucidated1 Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain; through a series of medical expert pools (the “ROME” process I, II, III, E-mail: [email protected] and IV). Diagnostic criteria are quite similar for children and adults . With regard to bowel movement disturbances, a constipation © 2018 Malagelada JR. This article is distributed under the terms of the Creative Commons Attribution 4.0 International predominant pattern is more common in children than3 a diarrhea License. predominant2-4 pattern or a mixed, alternating constipation/diarrhea pattern . Pattern shifts over time are rather common . IBS disease mechanisms so far identified are multiple, varied and not always fully understood. Pathophysiological features of IBS that are supported by solid scientific evidence include visceral hypersensitivity, gastrointestinal dysmotility, gut inflammation, dietary triggers, intestinal dysbiosis and5 disturbances of the gut-brain axis. Thus, IBS may be considered pathogenetically a heterogeneous entity, as recently reviewed . Familial aggregation is often noticeable but it is unclear whether genetic or environmental influences, including heightened awareness of abdominal sensations, are responsible. IBS is quite common in children as well as in adults. A well conducted, albeit relatively older study estimated that 14% of US high school students and 6% of6 middle school students suffer from symptoms consistent with8 IBS . More recent2, data4, 7 generally supports a very high prevalence of IBS in children and consequently a high economic burden . In clinical practice, an IBS diagnosis is not infrequently applied rather loosely since IBS is defined exclusively by a relatively complex symptom formula without a verifiable biological marker. Therefore, clinicians sometimes apply the IBS label to any patient without evidence of “definite” organic disease9 who complains of non-acute abdominal pain combined with altered bowel movement pattern. As pointed out by Quigley & Shanahan , a medical condition such as IBS, that is exclusively defined by symptom criteria, may create an illusion of understanding and equate complaints with “disease”. This aspect could be particularly relevant in children who may express symptoms vaguely and inconsistently. The real “intensity of complaints” may also be difficult to ascertain in this age group of patients. Stressful events affecting child and10, family 11 as well as attitudes and environmental factors are important . Page 21 of 27 Malagelada JR, Malagelada C. J Pediatr Pediatr Med. 2018; 2(3): 21-27 Journal of Pediatrics and Pediatric Medicine Prudent and carefully weighted application of pathogenetic role. However, more subtle forms of immune diagnostic tests is in order. A “positive” IBS diagnosis based nutrient-cell16, 17interactions may be at the root of IBS-like on symptom criteria should be attempted first, rather than symptoms . The challenge is to establish a definite an “exclusion” IBS diagnosis as traditionally undertaken responsibility for specific food products in the genesis of because the latter implies much higher iatrogenic risks and/ symptoms when simple observation yields only equivocal or economic burden. However, some basic evaluations way answers. A number of commercial tests are nowadays be warranted if in doubt, if family pressures are significant, available under the label “food intolerance tests”. These if prompt resolution is not achieved by application of include allergen-specific IgG reaction against various first line therapeutic measures and, of course, if alarm foods, electrodermal tests, sublingual or intradermal tests, clinical features are observed. The first commonly applied cytotoxic assays and others. Although several of these tests diagnostic examinations include blood test, stool check have elicited interest among physicians and, particularly, for parasites or blood, abdominal ultrasound exam and among the general public they have not reached solid endoscopic evaluation of the gastrointestinal tract. scientific approval and there are doubts as to whether test results truly reflect clinically relevant intolerance. Clinicians evaluating a child with abdominal symptoms Furthermore, there is mounting concern that unwarranted also need to pay attention to extraintestinal manifestations and radical diet restrictions may lead 18to nutritional and comorbid conditions such as fatigue, headaches, urinary studies imbalances including accumulation of metallic elemental and musculoskeletal12 symptoms etc as shown by IBS adult toxicants (i.e. mercury) in blood and tissues . The coincidence of these various symptomatic expressions in the same individual suggests CNS Non-allergic food intolerances are mainly related to participation distorting and integrating peripheral inputs a restricted capability of the gut to digest and absorb leading to the concept of central sensitizing disorders that sugars and other normal dietary components. Genuine may include IBS. Indeed, children with chronic digestive lactose intolerance is mostly due to low intestinal lactase symptoms show exaggerated 13brainstem responses to availability but it becomes19 clinically manifest only with surrounding stimuli and inadequate parental behaviours relatively large lactose loads, hence easily avoidable by appear to aggravate symptoms . Conversely, 14seemingly forewarned patients . Fructose, a monosaccharide present spontaneous resolution of IBS is not uncommon . in many processed foods, has a relatively low absorptive threshold in the human small bowel and consequently An IBS label in today´s hyper-communicated society fructose rich diets may produce gut symptoms 20in may also incorporate the15 conceptual elements of a “meme” susceptible individuals by stimulating intestinal motility . spreading by contagion among clinicians, relatives or Psychological factors may influence the symptomatic child-caring personnel . Symptoms themselves may response to sugar malabsorption21 as it has been well be potentially promoted and amplified by the child’s documented for lactose . Thus, subjective symptom entourage and even by medical personnel, eager to assessment represents a potential clinical confounding establish a diagnosis in a child with otherwise unexplained influence that must be taken into consideration. abdominal complaints. This mechanism could explain the increasing prevalence of IBS diagnosis in western societies The mechanisms of abdominal symptoms developing in Usefulboth in childrenpathophysiological and adults. features of IBS that may the context of nutrient malabsorption involve22 an increase help guide appropriate therapy in small bowel effluents entering the colon . In turn, these molecules are fermented by colonic bacteria increasing colonic production of gas and generating osmotic and If considering treatment for IBS, it may be useful to motility stimulants that induce colonic discharges and attempt to ascertain the pathogenetic mechanism or, at spasmodic bowel activity. There are, in addition to lactose least, the predominant pathophysiological disturbance and fructose, many incompletely absorbed carbohydrates effectivenessoperating in 5 individual patients, because a mechanism- in a normal diet that under certain circumstances may based approach probably improves therapeutic also produce colonic overload of fermentable substrates Diet composition,. tolerance and therapeutic generating gas, which is poorly tolerated by IBS patients. adjustments These include the group known as FODMAP (fructans, galactosaccharides and polyols including sorbitol, mannitol and xylitol) which are naturally present in Diet has the potential to act both as a symptom inductor many fruits and vegetables as well as in additives such and a therapeutic opportunity. It is self-evident that not as artificial sweeteners (Figure 1). Substantial evidence all children tolerate equally the multiple components of has accumulated indicating that a diet limiting FODMAP a normal diet. Specific food allergies may manifest in a components ameliorates IBS symptoms. Responders clinically obvious manner that leaves no doubt as to their appear to harbour more saccharolytic bacterial species in Page 22 of 27 Malagelada JR, Malagelada C. J Pediatr Pediatr Med. 2018; 2(3): 21-27 Journal of Pediatrics and Pediatric Medicine 32 as intraluminal small bowel fermentation . Changes in the colonic microbiome have also been implicated in IBS pathogenesis. Indeed, certain human microbiome